[s-cars] No Brake Assist

[Robert Myers]

The bomb is a structure vaguely reminiscent of the old German potato 
masher hand grenade of WWII.  It has a highly pressurized portion 
separated from the  hydraulic fluid by a membrane.  The PS pump 
pressurizes the PS fluid which "back flows" into the bomb against the 
diaphragm which maintains brake assist when the PS pump is not 
working (typically when the engine quits but it can also happen if 
the PS pump dies).  The test for a bad bomb it to let the system 
pressurize as engine runs.  Then turn off engine and repeatedly 
(counting) press the brake pedal until the pedal gets hard.  30+ the 
bomb is good.  20 or so keep watch on it.  10 - plan on repairs 
soon.  5 or less do it now.  Your test result is zero pumps.  Most 
likely the internal bomb diaphragm has ruptured but it may be 
possible to install a valve and repressurize the high pressure side 
of the bomb.


At 04:58 PM 10/23/2010, J R wrote:
>The hose from the pump to the bomb is right there where the 
>alternator goes in and out.  Could it be leaking?  I'm sure I moved 
>it around when pulling and reinstalling the alternator.  I don't see 
>any fluid leaking anywhere since I replaced the X-plug.
>
>JR
>
>
>On Sat, Oct 23, 2010 at 3:49 PM, Robert Myers 
><<mailto:bob at chips-ur-s.com>bob at chips-ur-s.com> wrote:
>*This message was transferred with a trial version of CommuniGate(r) Pro*
>
>It sounds like you now have no braking power assist at all.  Your 
>brake pressure accumulator (your "bomb") may be totally dead - or - 
>your PS pump may be totally dead.  The total loss of assist is the 
>test for a bad bomb.
>
>At 03:47 PM 10/23/2010, you wrote:
>*This message was transferred with a trial version of CommuniGate(r) Pro*
>
>I replaced my alternator and the X-Plug on my PS pump, and ever since I have
>no brake assist at all.  The brake light is on all the time.  The pedal is
>as hard as a rock and it is very very hard to stop the car.  Power steering
>is fine.  PS and brake fluid levels are fine.  Anyone have any idea what I
>might have bumped, broken or done wrong that would cause this?
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